Thermostat



FIG. 1 is a perspective view of a thermostat showing our new design;

FIG. 2 is a front elevational view thereof;

FIG. 3 is a first end view thereof, the opposite end being a mirror image of the end shown; and,

FIG. 4 is a first side view thereof, the opposite side being a mirror image of the side shown. 

The ornamental design for a thermostat, as shown and described. 